Product Information

The Wiseco fully forged pistons are rated very high in the street/strip performance industry. They offer several price levels of pistons, starting with the Pro-Tru Street version made with 4032 forged alloy. The next level up would be the Pro-Tru series that are much more expensive and made from 2618 aircraft alloy.

Our custom made Wiseco pistons are very close in comparison to the premium series as they are made using the 2618 aircraft alloy.

Some engine builders use the non-forged hypereutectic pistons, and we find them to be very risky for any carbureted street rod engine. We would not even consider using such pistons. If the pistons are non-forged or forged 4032 alloy, they may fragment from the effects of detonation. This can then allow the connecting rod to destroy the block, crank, and cylinder head. Those types of pistons are fine for stock or very mild engine builds, but should never be used in carbureted engines built to high horse power levels. These type of pistons, especially the hypereutectic version, will not stand much detonation. The forged 2618 alloy piston is so much more resistant to the effects of detonation, and heat.

Compression Ratio Chart

The calculations below assume your pistons are at zero deck. Let's say your compression calculates out to be 10.50 for example based on having the pistons at zero deck (flush with the deck), but your pistons were going to be .005 in the hole, then the comp. ratio would only drop to 10.36, and if left .010 in the hole, then it would drop to approx. 10.22 We do recommend having your block decked to allow the piston to set anywhere from flush (zero) to .005 in the hole for optimal performance. We used a 4.125 head gasket diameter, and a .040 head gasket thickness in our calculations to come up with our comp. ratio values.

We have highlighted in red the compression ratio for the bore size and piston volume of this assembly using several popular combustion chamber sizes.

Piston Family

Cylinder Head Volume

58cc

64cc

68cc

72cc

383

Static Compression Ratio

4.030 Bore

12.00

11.15

10.65

10.19

4.040 Bore

12.05

11.20

10.69

10.24

4.060 Bore

12.16

11.30

10.79

10.33

Our Wiseco Forged pistons are custom designed with an increase in compression height. This has many advantages. Here are a few facts about compression height and deck height.

Our custom made Wiseco pistons have a compression height that is .015 taller than nearly all catalog pistons on the market. We find this to be a very valuable feature. Since our pistons sit at a taller than normal compression height, you will only have to remove approx. .010 off the deck surface of a virgin block to achieve a zero deck. This also allows for future deck re-surfacing and still not ending too far below stock deck height.

Leaving the deck on your block thick makes for a stronger block that resists flexing and also runs cooler, as the deck thickness has a lot to do with the dissipation of heat. Blocks with decks cut down to any great amount are also prone to cracking. This is why our pistons are designed to sit flush, (zero deck) at .010 below stock deck height.

Since nearly all catalog pistons on the market sit .025 below the surface of a virgin block, the only way to achieve a zero deck using such pistons would be to cut .025 off the deck surface. This compromises the integrity of the block, in our opinion. Should you decide to leave the block deck higher up, using such pistons creates a new issue of having a very poor quench/squish zone. The only way you could really take advantage of a catalog piston is by having a block that needs to or has already been butchered down to 9.00 deck height. At that point, we don't think you should not use such a block. Having the piston sitting flush with the deck is very desirable, regardless of the fact that your overall compression ratio is slightly higher than if it were sitting below the deck.

We have found that 95% of our customers are using a virgin block or a block that is close to stock deck height. This is why we have designed our pistons to have a taller compression height. On very rare occasions, you may end up with a block that has the piston out of the hole by a few thousandths and this not a problem at all. Most head gaskets are approx. .040 thick, and should you end up with a quench zone of .035, then that is perfectly ok. If the quench zone ends up too far below .035, then there are plenty of .050 thick head gaskets on the market. One more benefit to this is that most machine shops charge much more to deck a block down from stock deck height to 9.00 than they would to do a light cleanup, and that's all that's needed when using our Wiseco pistons.

Another good feature about our pistons having a taller compression height is that the ring land above the top ring is much stronger by being .015 thicker. When pistons encounter the effects of detonation, it is not uncommon to see pistons with the ring land above the top ring broken off. The thicker ring land also makes a better heat sink.

You may have noticed that our Wiseco custom made forged pistons are referred to as Racing Pistons on the package. This does not mean that the pistons are for racing only. This is a generic term, referring to their ability to be used in high performance applications as well as for street rod use. These pistons are perfectly designed for use on the street, as well as for medium to upper level drag racing.

Our custom made Wiseco forged pistons are made from 2618 aircraft alloy. We find this alloy to be much more suitable for high performance engines than the common 4032 forged alloy. You will usually see the higher end pistons on the market using 2618 aircraft alloy.

Why go with 2618 forged pistons? If you encounter certain tuning issues, detonation is highly probable, and its effects can cause severe damage to your engine. The 2618 forged piston is able to withstand the damaging effects from detonation to a higher degree than the lower cost 4032 forged pistons, especially non-forged hypereutectic pistons such as Speed Pro or Keith Black, and many others.

Our Wiseco forged pistons will clear most any valve size on the market with ease even with the use of large lift cams.

We have built approximately 3500 engines using the Wiseco pistons. The engines have been for street rod and strip use. We have seen no problems, nor have there been any complaints. They are an excellent product in every respect.

These pistons are also suitable for use with nitrous systems up to approx. 250hp and superchargers up to approx. 15 to 17lb.s of boost. For the slight increase in cost, this is the best value on the market.

WISECO FULLY FORGED FLAT TOP PISTONS RATED AT 700+ HP. THIS AUCTION IS FOR A FULL SET OF PISTONS AND RINGS. WISECO PISTONS ARE 100% MANUFACTURED IN THE USA. THEY ARE ONE OF THE HIGHEST RATED PISTONS IN THE COUNTRY.

These pistons are for use with 6.0 full floating bushed rods, or press fit. The compression height is 1.140-4.5cc Flat top with 2 valve reliefs. Ring groove size 5/64 5/64 3/16. See full piston specs below.

THIS IS UNDOUBTEDLY THE BEST RING SET MADE FOR THESE PISTONS. DROP-IN, NO FILING REQUIRED.

HASTINGS 2M SERIES MOLY RINGS

Prefit Drop-In - Hastings Original Moly Ring Set - 5/64, 5/64, 3/16

Manufacturer: Hastings Mfg

Part #: 2M139

Item Code

KP451A3

Vendor
Name

WISECO

Product
Type

PISTONS,
CUSTOM MADE.

Product
Model

RACING
STREET/STRIP

Engine
Displacement (cu.in.)

383

Engine
Family

CHEVROLET
- Small Block V8

Material

2618
Forged Aluminum

Base
Bore (in)

4.000
+ 30

Stroke
(in)

3.750

Rod
Length (in)

6.0

Compression
Height (in)

1.140

Top
Type

FLAT
Top

Net
Head Volume (cc)

-4.5cc
valve reliefs

Deck
Thickness (in)

0.280

Wrist
Pin Diameter (in)

0.927

Wrist
Pin Length (in)

2.500

Wrist
Pin Weight (g)

Piston
Weight

APPROX.
122 grams.

APPROX.
536 grams.

Pin
Lock Type

Spiral

Ring
Set #

Hastings
DROP IN

Top
Ring Groove Size

5/64
in.

Second
Ring Groove Size

5/64
in.

Oil
Ring Groove Size

3/16
in.

Top
Ring Land (in)

0.255

Second
Ring Land (in)

0.170

Bottom
Ring Land (in)

0.090

Quantity

Sold
in sets of 8.

We offer these pistons in flat or dish style as well as dome top, and most other bore sizes. See our other listings.

Very Important Note!

Our sales staff has limited technical knowledge on this product and may not be able to answer many of the questions asked. Many of the questions asked are if we have pistons for certain applications. Please check our wide variety of pistons to see if what you need is listed. Be absolutely sure that you select the correct bore size and piston volume before purchasing. It is also important that you know what rod length you have. The rod length required is clearly stated in the ads. When searching for various size pistons, you can simplify your search by using common key words in the search bar. We update the technical information in our listings on a regular basis.

We are not responsible for collateral damage caused by the use of this product.